webkit自定义滚动条

::-webkit-scrollbar {
    width: 10px;
}
::-webkit-scrollbar-thumb:vertical{
    background-color:#A5A5A5;
    outline:2px solid #F6F6F6;
    outline-offset:-2px;
    border: 2px solid #F6F6F6;
    -webkit-border-radius:6px;
}
::-webkit-scrollbar-thumb:hover{
    background-color:#bcbcbc;
}